Telegraph transmitting key



July 30, 1940.

A. R. BONORDEN TELEGRAPH TRANSMITTING KEY Filed June 8, 1939 INVENTOR AR. BO/VORDE/V By QWQM ATTORNEY Patented July 30, 1940 uNrTso stares:

TELEGRAPH TRANSMT'ITING KEY Application June 8, 1939, Serial No. 278,037

Claims.

This invention relates to that class of lever keys which are employed for the purpose of closing and opening an electric circuit with rapidity to transmit over said circuit telegraphic signals according to the Morse or other analogous systerns of telegraphy.

The invention relates specifically to improvements in telegraph transmitting keys.

A principal object of the invention is to effect an economy of space in the operators keyshelf of a telegraph switchboard.

Heretofore in the design of switchboards in teletypewrlter exchange ofiices difiiculty has been encountered in attempting to mount two or more Morse transmitting keys in the limited space afforded in the operators keyshelves of telegraph switchboards. A previously known transmitting key, in general use, is mounted on trunnions and, in order to obtain the necessary rigidity against side movement the pivot or trunnion supports are spaced about 1 inches apart which, together with the adjusting screws make the overall width about 2% inches.

According to the present invention there is provided a narrow type of telegraph transmitting key which is of compact construction and whereof the contact-making points and other working parts are confined in a closed space so as to exclude all dust, fibres and other foreign substances from the working parts of the instrument. Its contact-making points and working parts are mounted below the level of the keyshelf of an. op-

erators switchboard, when the key is mounted for use. Its operating lever lies in a vertical plane and in this respect differs from the type ingeneral use, which has a long horizontal lever pivotally supported near its. mid-point by means or trunnions in suitable bearings. Its over-all width, including the finger-button, is about of an inch, or the width of a single line-up of operators lever type switching keys of a type such as disclosed in U. S. Patent 1,012,125, granted to E. B. Craft on December 19, 1911, and used in telephone switchboards. This width about onethird of that of the usual type of telegraph transmitting key.

Among the principal features or" the invention are: i

'(1) The economy of space afforded by the structural arrangement of the instrument;

(2) The avoidance of trunnions and their supporting members;

(3) The elimination of any lateral motion of the contact points;

(4) The assurance of making and breaking transmission circuits ina positive manner;

(5) The enclosure of the contact-making points and other working parts;

(6) The obscured means for locking the instrument in a make, or closed, position;'

(7) The separate methods of regulating and adjusting the distances through which the key operates in moving from a make to a break position and viceversa;

(8) T e provision of resilient members for effooting the make-and-break contacts;

(9) The rigidity of the instrument structure;

(10) The accessibility to all parts of the instrument for maintenance purposes.

In the "accompanying drawing:

Fig. 1 is the side elevation view of the transmitting key constituting the present invention;

Fig. 2 is the top plan View of Fig. 1;

Fig. 3 is the vertical cross-sectional view taken alon the dot and'dash lines 3-3 of Fig. 1;

Fig. 4 is the vertical cross-sectional view taken along the dot and dash lines l l of Fig. 1;

Fig. 5 is adetailed view of the camming arrangement whereby the key is locked in a closed position; i

Fig. 6 is the topplan view of an assembly of two keys of the type embodying the present in" vention and'a single line-up of push-pull keys mounted in an operators keyshelf; and

Fig. 7 is an alternative arrangement. of the operating contacts shown in Figs, 1 and 3.

All like parts in the figures of the drawing have like reference characters.

In the drawing, ll represents a top horizontal plate of bakelite or similar substance fixedly mounted by means of machine screws 5. on horizontal metallic base plate l3 having flanged sides as indicated in Figs. 3 and 4 and which may be identical'to the key base designated l in Patent 1,0l2;125, supra. Supported to the underside and within the side flanges of plate is by machine-screws is another metallic plate it. 7 Securelyfastened in grooves in opposite sides of metallic plate It by means of countersunk rivets, screws or other suitable means are two vertical metallic members it and it: and between the lower ends of members it and i5 is a horizontal metallic plate Ill, machine screws l8 serving to fasten plate ll securely to both members if: and

Ni. Y a I Disposed between corresponding ends of plates 14 and l I are threaded metallic rods l9 and 2!] on each of which two plane parallel surfaces have been milled the full length. Mounted on each of the two rods l9 and 20 as shown, are internally-threaded bushings 2|. A hexagonallyshaped shoulder is integrally formed on each bushing.

Referring to Fig. 1, metallic rod 19 at the top is fixedly disposed by staking or inserting it tightly into a punched oblong-shaped hole at the left end of plate l4 and at the bottom is finished in a threaded extension which engages a threaded hole in the left end of plate ll. Square-cut grooves are provided in the upper and the lower surfaces of the left end of plate [4 so that when rod I9 is inserted into the punched hole and filed on top to the level of the upper surface of plate it the milled surfaces of rod [9 will fit snugly against the sides of the grooves and the diffused top of the rod after filing will extend over the edges of the punched hole into the groove in the upper surface, thereby preventing the rod from rotating about its axis with respect to plates M and H. Plate I! is clamped in position on rod l9 by means of nuts 26. Metallic rod 20 has integrally formed therewith an extension arm 22 for supporting a finger-button 23 of insulative material. Rod 20 at the top slidably extends through an open slot in the right end of plate l4, a closed slot in the right end of base plate I3 and an open slot in the right end of bakelite plate H. Rod 20 at the bottom slidably extends through an open slot in the right end of plate ll. Rod [9 is fixedly mounted whereas rod 25 is slidably mounted and forms the operating key member.

Adjustably mounted between the upper portions of rods l9 and 20 is a fiat spring member 24 and between the lower portions of the same rods is a flat spring member 25. Each spring member is open-slotted, or bifurcated, at both ends to embrace closely the parallel surfaces of rods I9 and 20 and is also securely held in place, as shown, by means of bushings 2i and hexagonallyshaped nuts 26. Spring member 25 is normally maintained under a tension, that is, prestressed, by means of bushing 2i on the lower portion of rod 25. This prestressing may be reduced to the value desired by means of an adjusting screw 56 mounted through an adjusting nut 21, the screw 55 being in engageable relation with spring 24. The adjusting screw 56 may, as shown in Fig. 7 be mounted on plate H instead of plate H1 in which case the springs would be understressed initially and the adjusting screw advanced to increase the stress to the desired value. By prestressing one or both horizontal spring members 2 1 and 25 the operating rod 2!], controlled by key, or finger-button 23, may be caused to rest in a definite normal position as will hereinafter be described.

Fixedly mounted on rod 20 is an L-shaped insulative block 23 upon which is mounted a support 29. Support 29 serves both as a wiring terminal and a support for the resilient members 30. Fixedly mounted on and between the two vertical metallic members I5 and I6 is a metallic block 3|. Insulatedly mounted on opposite ends of block 3| are contact supports 32 and 33, through the ends of which are threaded capstan screws 34 and 35, respectively. A contact on the end of each of the capstan screws is in engageable relation with a contact on each of the resilient members 30. A round stud member 36 is rotatably mounted to extend through plates H, I13, and 14. To the lower end of the stud member is fixed a'circular disc 31 and to the upper end is fixedly mounted a knob 38 for rotating the stud and disc through a horizontal angle of about 30 degrees whereby a projecting lever 39 fixedly attached to disc 31 is placed in engagement with the cammed. edge of the upturned end of plate 40 to force, when knob 38 is turned, plate 40 and operating rod 20 downward to hold the operating rod in a fully depressed position when the key is not in use. A fiat spring member it is securely fastened at one end to the under-side of plate It and at the other end rests in a radially disposed groove on disc 31 to exert a pressure on the under-side of disc 31 to thereby hold the disc, and associated lever 39 out of engagement with plate 40 when the knob 38 is rotated preparatory to sending. In Fig. 5

projecting lever 39 is shown in cross-section in its normal position and in dot and dash line in its operated position, the lever not being in engagement with the cammed edge of the upturned end of bar 40 when it is desired to send.

The contact on the end of capstan screw 34 represents the spacing contact and that on the end of capstan screw 35, the marking contact. When the cam bar 40 is fully depressed as shown in dot and dash line in Fig. 5 the marking contact is closed, as when the key is not in use, that is, the key is normally held in a marking position. Conductors 42, 33 and 4d are shown in Fig. 1 connecting the marking, the spacing and a movable, or transfer, contact respectively to the main terminal block 45.

At opposite ends of the plate l3 are fixedly mounted internally-threaded studs 46 for engaging set screws 41 whereby the keys may be mounted in the keyshelf at an operators telegraph switchboard.

Fig. 6 shows the relative positions of two transmitting keys of the present invention and a single line-up of lever type switching keys mounted in the keyshelf of an operators switchboard.

An alternative arrangement of operating contacts, shown in Fig. 7, may provide a rigid make contact as used in the sending keys heretofore used. In such an arrangement an insulated contact may be aflixed to the bottom of operating rod 20 and the rod when operated serves to cause a contact on a resilient member 49 to engage with another contact afiixed to an adjustable screw 50. Resilient member 49 and adjustable screw 50 are insulatively mounted on plate ll and connected to terminals 45. A prestress adjusting screw 56 is shown in Fig. 7 as mounted in the lower plate I! instead of in the upper plate M as shown in Fig. 1.

What is claimed is:

l. A circuit make-and-break instrument comprising a contact, a second contact in engageable relation with the first-mentioned contact, an operable member on which said second contact is fixedly mounted, a fixed member, flexible members substantially parallel for supporting said operable member in a prestressed position from said fixed member and means for momentarily operating said operable member to a further stressed position whereby said second contact moves into engagement With the first-mentioned contact.

2. A circuit make-and-break instrument comprising an adjustable stationary contact, a resilient contact element in engageable relation with said stationary contact, an operable member, a fixed member, flexible members substantially parallel for supporting said operable member in a prestressed position from said fixed member, said flexible members adapted to restrict said operable member to a movement that is along its longitudinal axis, means for momentarily operating said operable member to a further stressed position whereby said resilient member moves into engagement with said contact, and adjustable means in engageable relation with one of said flexible members for regulating the amount of prestress normally applied to said operating member. r

3. A circuit make-and-break instrument com prising a pair of adjustable stationary contacts, a resilient contact element in engageable relation with each contact of said pair, an operable member on which said resilient element is fixedly mounted, a fixed member, flexible members substantially parallel for supporting said operable member in a prestressed position from said fixed member, means for momentarily operating said operable member to a further stressed position whereby said resilient element moves from one to the other contact of said pair and camming means for locking said operable member in a fully operated position.

4. A telegraph transmitting key comprising a square-shaped rigid structure whereof the contact-making points and other working parts are enclosed and the top is arranged to be mounted flush with the keyshelf of an operators switchboard, said structure having a width of a ratio of about 1 to 4 to each of its two other dimensions, an operable member controlled by said key and normally arranged in a prestressed position, a resilient element fixedly and insulatedly mounted on said operable member, and a pair of stationary contacts arranged to be alternately engaged by said resilient element depending on the operation of said operable member to its normal and its operated position.

5. A telegraph transmitting key comprising a square-shaped rigid structure whereof the top is arranged to be mounted flush with the keyshelf of an operators switchboard, and the contact-making points and other working parts are enclosed, said structure having a width of a ratio of about 1 to 4 to each of its two other dimensions, an operable member controlled by said key and normally arranged to be in a prestressed position, a resilient element fixedly and insulatedly mounted on said operable member, a pair of stationary contacts arranged to be alternately engaged by said resilient element in accordance with the operations of said operable member to its normal and its operated position, and means for further stressing said operable member any desired amount.

6. A telegraph transmitting key comprising a square-shaped rigid structure whereof the top is arranged to be mounted flush with the keyshelf of an operators switchboard and the contact-making points and other working parts are enclosed, said structure having a width of a ratio of about 1 to 4 to each of its two other dimensions, an operable element controlled by said key and normally arranged to be in a p-restressed position, a resilient element fixedly and insulatively mounted on said operable member, a pair of stationary contacts arranged to be alternately engaged by said resilient element in accordance with the operations of said operable member to its normal and opposite ends of said plates, a manually operated button fixedly mounted on top of said movable leg above said upper plate for operating said movable leg, aresilient element fixedly connected to the upper portions of said legs, a second rcsilient element fixedly connected to the lower portions of said legs, a movable contact-making resilient element fixedly connected insulatively to said movable leg, other contact-making elements adjustably mounted in engageable relation with said movable contaotmaking resilient element, supports for said other contact-making elements fixedly mounted on said rigid separator, and a clamp for locking said movable leg against movement. I

8. A circuit make-and-break structure of a narrow parallelopiped form having a ratio of its over-all width to either of its other two dimensions of about 1 to f]: and comprising an upper plate for fixedly mounting said structure in the keyshelf of an operators switchboard, a lower plate and a rigid separator interconnecting said plates, two vertically arranged rods at opposite ends of said plates, one of which is fixedly connected to the corresponding ends of said plates and the other movably arranged at the opposite ends of said plates, a manually operated button fixedly mounted on the top of said movable rod above said upper plate for operating said movable rod, a resilient element fixedly connected to the upper portions of said rods, a second resilient element fixedly connected to the lower portions of said rods, means employed for establishing said fixed connections adapted to exert a normal stress on said movable rod, a movable contact-making resilient element fixedly connected insulatedly to said movable rod and normally held in adefinite position, other contactmaking elements adjustably mounted in engageable relation with said movable contact-making resilient element, supports for said other contactmaking elements fixedly mounted on said rigid separator and a clamp for locking said movable rod against movement.

9. A circuit make-and-ibreak structure, ac cording to claim 8, wherein said resilient elements comprise adjustable means for determining the amount of movement of said movable rod.

10. A circuit make-and-break structure, according to claim 8, wherein said other contactmaking elements include adjustable means for determining the amount of movement and the amount of pressure exerted on said movable contact-making resilient element independently of the movement of said movable rod.

- ALLEN R. BONORDEN. 

